UBIFS: introduce compression mount options

It is very handy to be able to change default UBIFS compressor
via mount options. Introduce -o compr=<name> mount option support.
Currently only "none", "lzo" and "zlib" compressors are supported.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This commit is contained in:
Artem Bityutskiy 2008-11-01 14:57:49 +02:00
parent a1dc080c27
commit 553dea4dd5
5 changed files with 59 additions and 16 deletions

View File

@ -95,6 +95,9 @@ no_chk_data_crc skip checking of CRCs on data nodes in order to
of this option is that corruption of the contents
of a file can go unnoticed.
chk_data_crc (*) do not skip checking CRCs on data nodes
compr=none override defoult comressor and set it to "none"
compr=lzo override defoult comressor and set it to "lzo"
compr=zlib override defoult comressor and set it to "zlib"
Quick usage instructions

View File

@ -33,7 +33,7 @@
/* Fake description object for the "none" compressor */
static struct ubifs_compressor none_compr = {
.compr_type = UBIFS_COMPR_NONE,
.name = "no compression",
.name = "none",
.capi_name = "",
};
@ -43,13 +43,13 @@ static DEFINE_MUTEX(lzo_mutex);
static struct ubifs_compressor lzo_compr = {
.compr_type = UBIFS_COMPR_LZO,
.comp_mutex = &lzo_mutex,
.name = "LZO",
.name = "lzo",
.capi_name = "lzo",
};
#else
static struct ubifs_compressor lzo_compr = {
.compr_type = UBIFS_COMPR_LZO,
.name = "LZO",
.name = "lzo",
};
#endif

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@ -179,8 +179,11 @@ static int create_default_filesystem(struct ubifs_info *c)
sup->fanout = cpu_to_le32(DEFAULT_FANOUT);
sup->lsave_cnt = cpu_to_le32(c->lsave_cnt);
sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION);
sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);
sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN);
if (c->mount_opts.override_compr)
sup->default_compr = cpu_to_le16(c->mount_opts.compr_type);
else
sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);
generate_random_uuid(sup->uuid);
@ -582,16 +585,15 @@ int ubifs_read_superblock(struct ubifs_info *c)
c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
c->fanout = le32_to_cpu(sup->fanout);
c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);
c->default_compr = le16_to_cpu(sup->default_compr);
c->rp_size = le64_to_cpu(sup->rp_size);
c->rp_uid = le32_to_cpu(sup->rp_uid);
c->rp_gid = le32_to_cpu(sup->rp_gid);
sup_flags = le32_to_cpu(sup->flags);
if (!c->mount_opts.override_compr)
c->default_compr = le16_to_cpu(sup->default_compr);
c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
memcpy(&c->uuid, &sup->uuid, 16);
c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
/* Automatically increase file system size to the maximum size */

View File

@ -417,6 +417,11 @@ static int ubifs_show_options(struct seq_file *s, struct vfsmount *mnt)
else if (c->mount_opts.chk_data_crc == 1)
seq_printf(s, ",no_chk_data_crc");
if (c->mount_opts.override_compr) {
seq_printf(s, ",compr=");
seq_printf(s, ubifs_compr_name(c->mount_opts.compr_type));
}
return 0;
}
@ -878,6 +883,7 @@ static int check_volume_empty(struct ubifs_info *c)
* Opt_no_bulk_read: disable bulk-reads
* Opt_chk_data_crc: check CRCs when reading data nodes
* Opt_no_chk_data_crc: do not check CRCs when reading data nodes
* Opt_override_compr: override default compressor
* Opt_err: just end of array marker
*/
enum {
@ -887,6 +893,7 @@ enum {
Opt_no_bulk_read,
Opt_chk_data_crc,
Opt_no_chk_data_crc,
Opt_override_compr,
Opt_err,
};
@ -897,6 +904,7 @@ static const match_table_t tokens = {
{Opt_no_bulk_read, "no_bulk_read"},
{Opt_chk_data_crc, "chk_data_crc"},
{Opt_no_chk_data_crc, "no_chk_data_crc"},
{Opt_override_compr, "compr=%s"},
{Opt_err, NULL},
};
@ -950,6 +958,28 @@ static int ubifs_parse_options(struct ubifs_info *c, char *options,
c->mount_opts.chk_data_crc = 1;
c->no_chk_data_crc = 1;
break;
case Opt_override_compr:
{
char *name = match_strdup(&args[0]);
if (!name)
return -ENOMEM;
if (!strcmp(name, "none"))
c->mount_opts.compr_type = UBIFS_COMPR_NONE;
else if (!strcmp(name, "lzo"))
c->mount_opts.compr_type = UBIFS_COMPR_LZO;
else if (!strcmp(name, "zlib"))
c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
else {
ubifs_err("unknown compressor \"%s\"", name);
kfree(name);
return -EINVAL;
}
kfree(name);
c->mount_opts.override_compr = 1;
c->default_compr = c->mount_opts.compr_type;
break;
}
default:
ubifs_err("unrecognized mount option \"%s\" "
"or missing value", p);
@ -1100,13 +1130,13 @@ static int mount_ubifs(struct ubifs_info *c)
goto out_free;
/*
* Make sure the compressor which is set as the default on in the
* superblock was actually compiled in.
* Make sure the compressor which is set as default in the superblock
* or overriden by mount options is actually compiled in.
*/
if (!ubifs_compr_present(c->default_compr)) {
ubifs_warn("'%s' compressor is set by superblock, but not "
"compiled in", ubifs_compr_name(c->default_compr));
c->default_compr = UBIFS_COMPR_NONE;
ubifs_err("'compressor \"%s\" is not compiled in",
ubifs_compr_name(c->default_compr));
goto out_free;
}
dbg_failure_mode_registration(c);
@ -2023,8 +2053,8 @@ static int __init ubifs_init(void)
/*
* We use 2 bit wide bit-fields to store compression type, which should
* be amended if more compressors are added. The bit-fields are:
* @compr_type in 'struct ubifs_inode' and @default_compr in
* 'struct ubifs_info'.
* @compr_type in 'struct ubifs_inode', @default_compr in
* 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
*/
BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);

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@ -893,13 +893,21 @@ struct ubifs_orphan {
/**
* struct ubifs_mount_opts - UBIFS-specific mount options information.
* @unmount_mode: selected unmount mode (%0 default, %1 normal, %2 fast)
* @bulk_read: enable bulk-reads
* @chk_data_crc: check CRCs when reading data nodes
* @bulk_read: enable/disable bulk-reads (%0 default, %1 disabe, %2 enable)
* @chk_data_crc: enable/disable CRC data checking when reading data nodes
* (%0 default, %1 disabe, %2 enable)
* @override_compr: override default compressor (%0 - do not override and use
* superblock compressor, %1 - override and use compressor
* specified in @compr_type)
* @compr_type: compressor type to override the superblock compressor with
* (%UBIFS_COMPR_NONE, etc)
*/
struct ubifs_mount_opts {
unsigned int unmount_mode:2;
unsigned int bulk_read:2;
unsigned int chk_data_crc:2;
unsigned int override_compr:1;
unsigned int compr_type:2;
};
/**